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Biomedical subjects

A Lanzone

Publications and source records attributed to A Lanzone.

At least 145 records · Page 8Linked to original sources
PubMed1989

Effect of gonadotrophin-releasing hormone and related analogue on human luteal cell function in vitro.

The possible direct effect of gonadotrophin-releasing hormone (GnRH) and GnRH agonist (GnRH-A; buserelin) on basal and human chorionic gonadotrophin (HCG)-stimulated progesterone (P) and cyclic AMP (cAMP) production by cultured human luteal cells was examined. Luteal cells from the early or mid-luteal phase were incubated in long-term cultures. They responded to HCG stimulation with a 2- to 3-fold increase in P production and a 2-fold increase in cAMP production. The addition of GnRH (10(-7) and 10(-5) M) or GnRH-A (10(-7) and 10(-5) M) to the medium had no effect on either basal or HCG-stimulated secretion. These results indicate that both GnRH and GnRH-A have no direct effect on human luteal steroidogenesis in vitro.

Adult↗
PubMed1989

Effect of luteal metoclopramide-induced hyperprolactinemia on pituitary and luteal responsiveness to gonadotropin-releasing hormone.

The pituitary and corpus luteum responses to acute gonadotropin-releasing hormone (GnRH) administration at the mid-luteal phase (LP) were studied in 24 infertile women. Patients were randomly divided into two groups. In one group (n = 12) metoclopramide (MCP, 10 mg orally 3 times daily) was administered from day 0 or 1 of the LP for 7 days. On day 7 or 8 of LP blood samples were taken every 15 min for 180 min; then 25 micrograms GnRH were acutely administered intravenously and blood samples taken at 185, 195, 210, 225, 240, 255, 270, 285 and 300 min. In the other 12 patients the same experimental design was performed on day 7 or 8 of an untreated LP. Plasma prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone and estradiol (E2) were assayed. The responsiveness of the different hormones to GnRH was evaluated as the integrated secretory area for 120 min after injection (sISA = stimulated integrated secretory area) and as the percentage increase (delta A) with respect to the area under basal conditions before GnRH administration (bISA = basal integrated secretory area). MCP-treated women showed higher basal PRL levels (p less than 0.01) and lower basal plasma concentrations and bISA (p less than 0.01) values of LH than controls. After GnRH a more marked response of LH secretion was observed in the treated group (p less than 0.01), so that the absolute values of sISA were superimposable in both groups. Basal and stimulated FSH secretion did not differ significantly in the study groups. Basal plasma and bISA values of progesterone were also decreased in MCP-treated subjects. After GnRH injection the absolute values of progesterone sISA were greater in controls (p less than 0.01), but delta A values were similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Effect of human chorionic gonadotropin administration on pituitary and luteal response to gonadotropin-releasing hormone.

The effect of human chorionic gonadotropin (hCG) administration on the pituitary and luteal responses to acute gonadotropin-releasing hormone (GnRH) administration at the mid luteal phase (LP) were studied in 20 infertile women. Patients were divided into 2 groups. In 1 group (n = 8), hCG (5,000 IU i.m.) was injected in a single shot on day 5 of LP. Sixty hours later (day 8 of LP) blood samples were taken every 15 min for 180 min; then 25 micrograms GnRH were acutely administered intravenously and blood samples taken at 185, 195, 210, 225, 240, 255, 270, 285 and 300 min. In the other 12 patients the same experimental design with GnRH was performed on day 8 of an untreated LP. Plasma LH, FSH, beta-hCG, progesterone and estradiol (E2) were assayed. The responsiveness of different hormones to GnRH was evaluated as integrated secretory area for 120 min after injection (sISA) and as the absolute increase with respect to the area under basal conditions before a GnRH administration (bISA). hCG-treated patients showed higher basal and bISA plasma values of LH/hCG than controls (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

LH surge induction by GnRH agonist at the time of ovulation.

Eight women were treated for 1 cycle at the time of ovulation with GnRH agonist (3 injections of 0.2 mg buserelin s.c. at 12-hour intervals) to obtain follicular rupture. Clomiphene citrate was administered to 1 patient and pure FSH to 2 patients, whilst in the case of a woman with hypothalamic amenorrhea a pulsatile GnRH regimen was used. Four patients had an untreated follicular phase. When the maximal follicular diameter was 20-22 mm all treatments were withheld and GnRH-A was administered. Plasma LH, FSH, progesterone and estradiol were determined 24 hours before, at the time of and 12, 24 and 48 hours after the 1st injection of buserelin. Ovulation was detected in all cycles. LH levels increased dramatically from baseline levels of 14.4 +/- 4.1 to 155 +/- 48 IU/l 12 hours after the beginning of treatment, then returned to preovulatory values 48 hours later (13.0 +/- 3.9 IU/l). The duration of the luteal phase was 13.2 days and normal mid-luteal progesterone plasma levels were detected (39.8 +/- 9.3 nmol/l). These data suggest that the GnRH agonist can be successfully used at the time of ovulation to induce an endogenous ovulatory LH peak and that it can be used in conjunction with different medical treatments to induce follicular maturation.

Adult↗
PubMed1988

Des-acetyl-alpha-MSH and not alpha-MSH is the major form of alpha-MSH in amniotic fluid.

Immunoreactive alpha-melanocyte stimulating hormone (IR-alpha-MSH)-like activity was measured by radioimmunoassay (RIA) in at term pregnancy amniotic fluid prior and after adsorption on a Sep-pak C18 cartridge. alpha-MSH activity was 3-4 times lower after Sep-pak purification but, unlike the levels of IR-alpha-MSH in the fluid analyzed in toto, increased linearly with the volume of fluid analyzed. Furthermore, fractionation by high pressure liquid chromatography (HPLC) revealed that IR-alpha-MSH recovered from the Sep-pak was due to several peptides rather than to a single peptide. The most abundant of them (50% of total activity) behaved like authentic des-acetyl-alpha-MSH. Since des-acetyl-alpha-MSH is also the most abundant alpha-MSH-like peptide in the fetal pituitary gland, the present results suggest that the fetal pituitary is a main source of des-acetyl-alpha-MSH in the amniotic fluid.

Amniotic Fluid↗
PubMed1987

Continuous subcutaneous insulin infusion (CSII) in pregnant diabetic patients.

The efficacy of the insulin infusion pump (CSII) in pregnancy was examined in 12 diabetic patients and compared with intermittent insulin therapy (IIT). In patients poorly controlled on IIT constant and rapid equilibrium was achieved with CSII (mean of glucose levels: CSII versus IIT = 84 versus 137 mg/dl; S.D. = 36 versus 63 mg/dl; mean amplitude of glycemic excursion (MAGE) = 65 versus 112 mg/dl. In patients well controlled on IIT, CSII led to a reduction in the variation of glucose excursions (S.D. = 29 versus 36 mg/dl; MAGE = 48 versus 76 mg/dl). CSII generally produced a reduction of 20-37 per cent of daily insulin dose (in three cases there was an increase of dose with the achievement of glycemic control). Furthermore in CSII treated-patients amniotic glucose, insulin and C-peptide concentrations were found to be in the normal range (22.1 +/- 10.1 mg/dl; 5.2 +/- 2.7 microU/ml; 1.25 +/- 0.71 ng/ml, respectively). All infants were born at or near-term, had no macrosomia or neonatal problems. It is concluded that CSII is a highly efficient way to achieve normal glucose levels in pregnancy, not only in type I, but also in type II or gestational diabetes.

Adult↗
PubMed1987

The impact of dosage on ovulation induction by pulsatile gonadotropin-releasing hormone (Gn-RH) in hypothalamic amenorrhea.

Ten patients with hypothalamic amenorrhea (HA) were treated to induce ovulation with i.v. pulsatile Gn-RH. Twentysix cycles were administered with doses ranging from 2.5 (A; no. = 10) to 5 (B; no. = 13) to 10-12.5 micrograms/90 min (C; no. = 3). Ovulation rate was 80% in A, 92.3% in B and 100% in C and pregnancy rate 25% in A and 41.6% in B. Furthermore, both the onset of ovarian response and follicular growth were found to be more suitable in groups B and C with respect to group A. Estradiol pattern as well as mid-luteal progesterone plasma levels were superimposable in the different groups. It is concluded that all doses used are effective in inducing ovulation in HA patients. However, small pulsatile doses (2.5 micrograms/90 min) might constitute a critical threshold for adequate ovarian response.

Amenorrhea↗
PubMed1987

Induction of ovulation by intermittent intravenous purified follicle-stimulating hormone in polycystic ovarian disease.

IIV FSH was administered to eight women with PCOD to induce ovulation. These patients had been previously treated unsuccessfully with CC or IM gonadotropins. The drug was administered by a pump at 120-minute intervals. Dosage was 1 ampule Metrodin (75 IU of FSH less than 0.11 IU of LH)/day. Eight cycles of treatment were effected. With the IIV regimen, ovulation rate was 75% (six cycles). Two multiple pregnancies and one abortion (mola vescicularis) were observed. Preovulatory E2 plasma levels and the number of follicles recruited per cycle varied from 530 to 3800 pg/ml and from 4 to 15, respectively. Maximal follicular diameter was between 16 and 28 mm. LH levels significantly decreased, while FSH levels were unchanged, resulting in a decrease of LH/FSH ratio. It is concluded that the IIV FSH regimen offers an additional modality for the induction of ovulation in PCOD patients. Further clinical trials with alternative regimens are needed, however, to identify the optimal dosage and frequency of administration of the drug.

Adult↗
PubMed1987

Luteal responses to gonadotropin-releasing hormone during the luteal phase: relation to the age of corpus luteum.

The pituitary and luteal responsiveness of GnRH were studied in 20 normal women at different stages of the luteal phase (LP). Blood samples were collected every 15 min for 180 min before and 120 min after the iv injection of 25 micrograms GnRH. The studies were performed in the early LP (ELP; days 2-3 of LP; n = 5), mid-LP (MLP: days 4-8 of LP; n = 11), late LP (LLP; days 9-12 of LP; n = 13), and premenstrual phase (PMP; days 13-14 of LP; n = 3). Plasma LH, FSH, progesterone (P), and estradiol (E) levels were assayed by RIA. The data were analyzed as integrated secretory area before (ISAb) and after GnRH stimulation (ISAs) and in terms of their percent increase with respect to the basal value. In all studies, GnRH elicited increases in plasma LH and FSH (P less than 0.001). On the other hand, in the ELP, GnRH did not alter steroid ISAs compared to their ISAb, while significant increases in plasma P and E levels were found in the MLP (P, P less than 0.01; E, P less than 0.02) and LLP (P and E, P less than 0.01). In the PMP, two women had no increase in steroid secretion; in the remainder of the subjects, both P and E ISAs markedly increased. This different pattern was not related to basal steroid levels. All women who had a blunted steroid response in the ELP or PMP had a normal secretory response of both P and E when studied at the other LP stages of the same cycle. Furthermore, there was a positive linear correlation between plasma P and E for the ISAb and ISAs values, while the secretory patterns of gonadotropins and steroids were not related to each other. In conclusion, the corpus luteum is able to respond to GnRH to GnRH at a well identified period of the LP. This pattern indicates variable dependence of the corpus luteum on the functional activity of the hypothalamic-pituitary axis.

Adult↗
PubMed1987

Successful induction of ovulation and conception with combined gonadotropin-releasing hormone agonist plus highly purified follicle-stimulating hormone in patients with polycystic ovarian disease.

Five women (group A) with polycystic ovarian disease (PCOD) and sterility for at least 3 yr were treated for 1 cycle for ovulation induction with a combined regimen of GnRH agonist (GnRH-A) plus highly purified FSH. The patients received GnRH-A (Buserelin; 200 micrograms, sc, twice a day) for 6 weeks and then GnRH-A combined with FSH highly purified (2 ampules a day; 75 IU FSH and less than 0.11 IU LH in each ampule). Ovarian response was evaluated by plasma estradiol (E2) assay and ultrasound examination, performed daily. Furthermore, plasma FSH and LH levels were assayed 3 times a week. Once a follicle was considered sufficiently developed, the combined regimen was withheld, and 24-48 h later hCG (5000 IU, im) was given. The results are compared with those of 31 ovulatory cycles induced by im FSH highly purified (group B) in PCOD patients with the same FSH administration, clinical, and monitoring protocols. Ovulation was achieved in all cycles treated by GnRH-A plus FSH. Two singleton and a twin pregnancy resulted. Multiple follicular development occurred in all cycles. Plasma E2 levels were generally in the normal range. Echographic and endocrine features in the 2 groups were as follows. 1) basal ovarian volume and ovarian enlargement were similar. 2) Group A had a greater number of follicles than did group B (P less than 0.01), while E2 to number of follicles and E2 to ovarian volume ratios were greater (P less than 0.01) in group B. 3) The linear correlations between plasma E2 levels and ovarian volume were markedly different in groups A and B (P less than 0.01). The regression line for group B had a steeper slope than that for group A. This finding indicates that at a fixed ovarian volume plasma E2 levels were significantly lower in group A than in group B. We conclude that the combined GnRH-A and FSH regimen may constitute an alternative and promising tool for the induction of ovulation in patients with PCOD.

Adult↗
PubMed1986

Progesterone and LH variations after LH-RH administration in the luteal phase of the menstrual cycle.

We have investigated the pituitary and luteal responses to LH-RH and their related changes. 11 normal women were studied during the luteal phase (day +4/+11). Blood samples were collected every 15 min for a basal period of 180 and 120 min after the intravenous administration of 25 micrograms of LH-RH. Progesterone (P) and LH were assayed by radioimmunoassay. Data were analyzed as maximum peak and its percent increase (delta max), integrated secretory area (ISA) and percent increase of ISA (delta A) in respect to basal values for both P and LH. LH-RH elicited a secretory response of both hormones in all cases. ISA of LH was significantly greater after LH-RH administration in respect to basal values (p less than 0.001) and delta max accounted to 475 +/- (SE) 36% of the basal concentration. Luteal responsiveness varied from about 115-130% to more marked increments. ISA of P differed from basal to stimulated conditions (p less than 0.05) and delta max was 166 +/- (SE) 14%. The analysis of temporal relationship between P and LH secretion showed that LH promptly rose after LH-RH, while the enhancement of P plasma levels occurred within 31 +/- 19 min after LH rise. Then P levels reached a plateau, values of which were statistically different from those observed before LH-RH administration. In two cases where luteal function was blunted or absent, in spite of marked increments of LH, P secretion did not occur. These data are consistent with the presence of close relationships between hypothalamic, pituitary and luteal functions and strengthen the contention about the usefulness of LH-RH during luteal phase for the lifespan and maintenance of corpus luteum.

Adult↗
PubMed1986

Continuous subcutaneous insulin infusion (CSII) in pregnant diabetic women.

Insulin infusion pump treatment (CSII) in pregnancy was compared with conventional therapy (IIT) in 12 pregnant diabetic women. In patients poorly controlled on IIT a plasma glucose equilibrium was achieved with CSII (mean of: glucose levels = 84 vs 137 mg/dl; SD = 36 vs 63 mg/dl; MAGE = 65 vs 112 mg/dl). In patients well controlled on IIT, CSII led to a reduction in the variation of glucose excursions (SD = 29 vs 36 mg/dl; MAGE = 48 vs 76 mg/dl). CSII generally led to a reduction of 20-37% of daily insulin dose but in 3 cases there was an increase of dose with the achievement of glycaemic control. A significant relation between bolus/basal ratio of insulin daily dose and the quality of glycaemic control was also found during CSII. All infants were born at or near to term and none were macrosomic or had neonatal complications. It is concluded that CSII is highly efficient in pregnancy not only in type I but also in type II or gestational diabetes.

Adult↗
PubMed1983

Uptake, receptor and biological response of estrone in the fetal uterus of guinea pig.

In vivo and in situ subcutaneous injection of 30 muCi of 3H-estrone (3H-E1) to guinea pig fetuses was carried out to study the dynamics of the selective uptake and retention of this estrogen in the uterus and other fetal organs. In the fetal uterus an increase in the uptake of radioactivity with time was found which was maximal 1 h after injection of 3H-E1. The analysis of radioactive material showed that in the fetal uterus unmetabolized 3H-E1 accounts for 65-75% of the total radioactivity between 10 and 60 min after the injection and its maximal concentration is 2.5-15 times and 10 times higher than the maximal concentrations found in other fetal organs and fetal plasma, respectively. Significant amounts of 3H-E1 were also present in lung (33-60% of the total radioactivity in this tissue), brain (37-52%) and ovary (18-47%), while an important conversion of 3H-E1 into 3H-estradiol was observed in the kidney (20-26%). Estrogen sulfates, essentially estrone sulfate, represented the greater part of the fetal plasma radioactivity (30-49%). 3H-E1-specific binding sites in the cytosol of the fetal uterus were found with physicochemical characteristics (specifically limited to natural and synthetic estrogens, Kd = 8.1 +/- 1.2 x 10(-10) M (SD), sedimentation coefficient 8S) similar to those of the typical estrogen receptor. The cytosol receptor-3H-E1 complex has a dissociation rate constant (K-1) of 16 +/- 0.7 x 10(-4) s-1 at 25 degrees C. The responsiveness of the fetal uterus to estrone treatment was studied after subcutaneous administration of estrone to pregnant guinea pigs (1 mg/kg/day for 3 consecutive days). Two biological responses were observed: an increase in fetal uterine weight (50-100% in relation to the nontreated animals) and a significant stimulation of progesterone receptor protein (10-16 times higher than in control animals). At the same time, there was a 50-70% decrease in the total estrogen receptor concentration. It is concluded that estrone could be involved in the biological responses to estrogen in the fetal uterus of guinea pig.

Animals↗
PubMed1982

Effects of seven different oestrogen sulphates on uterine growth and on progesterone receptor in the foetal uterus of guinea pig after administration to the mother.

The biological effect of seven different oestrogen sulphates: oestrone-3-sulphate (E1-3-S), oestradiol-3-sulphate (E2-3-S), oestradiol-17-S), oestradiol-3,17-disulphate (E2 3,17-DS), oestriol-3-sulphate E3-3-S), oestriol-17-sulphate (E3-17-S), oestriol-3,16,17-trisulphate (E3-3,16,17-TS), was studied in the foetal uterus of guinea pig (55--65 days of gestation) after sc administration for 3 consecutive days of each sulphate to the mother. On day 4, two response parameters were investigated, the uterotrophic effect and the action on the progesterone receptor. The monosulphates at the C3 position of the oestrogens (E1-3-S, E2-3-S and E3-3-S) provoked an increase in uterine weight of 1.9--2.4 times in relation to the non-treated animals. These oestrogen sulphates also very significantly stimulated the number of progesterone specific binding sites, 7--10 times in relation to the non-treated animals. On the other hand, when the sulphate was at C17 of the oestrogens (E2-17-S, E3-17-S, E2-3-17-DS, E3-3,16,17-TS), very little or no effect on the foetal uterus was observed on the two parameters studied. It is concluded that oestrogen (oestrone, oestradiol, oestriol) sulphates in position C3 can be involved in the biological response to the hormone and it is suggested that the effect is carried out after the hydrolysis of the sulphate. On the other hand, sulphates in C17 are not hydrolysed and no significant biological effects were observed in the uterine growth or in the progesterone receptor.

Animals↗
PubMedDate not supplied

Naltrexone effect on pulsatile GnRH therapy for ovulation induction in polycystic ovary syndrome: a pilot prospective study.

The aim of the present study was to analyze the opioid influence on LH pulsatility in polycystic ovary syndrome (PCOS) patients and to evaluate the effectiveness of a long-term opioid antagonist (naltrexone) treatment in improving the pulsatile GnRH therapy which is successful in this syndrome. Ten obese women affected by PCOS participated in the study. Patients were hospitalized during the early follicular phase and underwent an oral glucose tolerance test (OGTT) with 75 g of glucose and a pulse pattern study followed by a GnRH test (100 pg i.v.). All patients were then treated for ovulation induction with pulsatile administration of GnRH (5 microg/bolus every 90 min). Since pregnancies did not occurr in any patient, after spontaneous or progestin-induced menstrual cycles, all patients received naltrexone at a dose of 50 mg/day orally for 8 weeks and during treatment repeated the basal protocol study and the ovulation induction cycle with the same modalities. The naltrexone treatment significantly reduced the insulin response to OGTT and the LH response to GnRH bolus, whereas it did not affect the FSH and LH pulsatility patterns. Concerning the ovulation induction by pulsatile GnRH, naltrexone treatment was able to improve, although not significantly, the ovulation rate (60% pre-treatment vs 90% post-treatment). Furthermore, the maximum diameter of the dominant follicle and the pre-ovulatory estradiol concentration were higher after long-term opioid blockade (follicular diameter 19.5+/-1.76 mm pre-treatment vs 21.6+/-2.19 mm post-treatment, p<0.001; maximum estradiol level 728.7+/-288.5 pmol/l pre-treatment vs 986.4+/-382.1 pmol/l post-treatment, p<0.05). During the naltrexone-pulsatile GnRH co-treatment two pregnancies occurred. In conclusion, our data show that naltrexone-pulsatile GnRH co-treatment is able to improve the ovarian responsiveness to ovulation induction in obese PCOS patients when compared to pulsatile GnRH alone. This action seems to be related to a decrease of insulin secretion. Further randomized studies should be performed in order to obtain significant conclusions on the possible clinical application.

Adult↗